A method of injection-moulding a zipper slide with pull tab is described in European Patent No. 0 282 987. According to this Patent document, the slide body is injection-moulded in a first injection step. The bow on the slide body, which later receives the pull tab, is formed by an inserted mould core with a displaceable auxiliary core lying therein. The auxiliary core is withdrawn in order to injection mould the pull tab. Thus there results an injection duct which passes through underneath the bow of the slide body. Thereafter the injection mass for the pull tab is injected. The mould core is then again withdrawn from the mould, before ejection of the completed zipper slide with pull tab.
A disadvantage of this method is that the injection procedure is effected in two steps. In addition, before injecting the pull tab there must be a delay until the material of the slide body has hardened sufficiently so that the material of the pull tab does not combine with that of the body, as the injected material for the pull tab comes into direct contact with that of the slide body.
A purpose of the present invention is to indicate a method by means of which the zipper slide body and the pull tab may be manufactured in one single injection step. Such a method is indicated in claim 1. The further claims define preferred embodiments, tools for carrying out the method and zipper slides produced thereby.